X50 Head build & Setup

[DaweMD]

Guys I am including some pics of my head setup so I can get some opinions back on how it looks. I just replaced my Hitec cyclic servos with these Savox SC-1258TG’s, they seem like they should have enough torque and speed so I could run flybarless down the road. They only thing I have found about them so far is that they are noisy when just sitting there, they were fine without any servo arms but as soon as they went on there they got noisy. Sometimes if I bounce the sticks around a little they go quiet again. This was a new build for me so the linkages are stiff, maybe that’s why they are noisy?
My swash mix is set @ Aile & Elev both set at 60% and pitch is set at 55%(Gives me +15/-15). Travel adjust are all set at 100%, Sub trims are Aile: L32, Elev: D33, Pitch: L40. While these numbers seem high it seemed to be the best I could get in order to have the head come out like the pics.
I tried using a leveling tool that I got from Espirit models but it did not help me. I have 2 other 450 size heli’s that I have used leveling tools on before and they worked without any issue, this heli I can’t figure out! I go to mid stick and adjust linkage to make the swash go straight, than go to top stick and adjust travel adjust to make things right, than go to low stick and do the same. This is where it gets weird – I go back to top stick and it is out of adjustment again! As I go through the stick positions it will change every time until I am at 0% travel adjust on the low side! Maybe someone can tell me what I am doing wrong.
Thanks guys.

[YBNORMAL]

Everything looks in order mechanically, the only thing I can think of is to try not to use the "pitch" servo to level the swash at max up or down on the swash. Depending on the reversing and swash values being used, using the 'pitch' servo to level the swash will move the opposite end of travel than what your Tx is telling you the servo is at.

What you are describing sounds like this may be your issue.

YB

[DaweMD]

Thanks for the feedback.

[Elgyn]

did you re-size the ball links? I had to on mine to get and any nomal movement. Too tight from the factory

[Bob O]

It's not real easy to tell from your pics, but there are some mechanical setup issues.

First, the swash appears to be tilted to the right.

Second, the bell crank linkages are not equal length, which means that the servo arms are not lined up properly with the bell cranks. The elevator servo appears to be set up properly, however the two forward servos are not.

Here's a link to some pics that I drew lines on to show what you want to strive for as far as getting the servos and bell cranks set up properly. Also take a look through KouDy's build thread, there's possibly some useful information in there.

https://www.helifreak.com/showpost.p...1&postcount=82

Sorry, have to get to work now. Hope this helps.

[DaweMD]

Thanks Bob O, will have a look at the attached link.

[DaweMD]

I noticed yours is 140 Deg I believe mine is factory 120 Deg, will that make a difference?

[Bob O]

Originally Posted by DaweMD

I noticed yours is 140 Deg I believe mine is factory 120 Deg, will that make a difference?

No, the idea of everything being square, 90'ed, etc is the same from one setup to the next. I've since switched to 120 degree control. The only thing that changed was the length of the bell crank linkages.

Sent from my phone

[DaweMD]

What did you have for the length of the bell crank linkages with the 120 Deg?

[DaweMD]

What are you using for Ball distance from the center of the servo?

[DaweMD]

Forget those last 2 comments, figured it out. I will take some pics and post them tonight. Thanks again.

[YBNORMAL]

So what was it?

YB

[DaweMD]

I had 22.60mm center of ball to center of ball.

[DaweMD]

After another couple of nights tinkering with the servo wheels and linkages I think I have come as close as I can get. I have included pics of my final setup.
Pitch with this setup is giving me +12 to -12. Aileron is +/-8 Deg. My swash settings are as follows:
Aile = -40%
Elev = -40%
Pitch = +48%
Sub Trims are set to:
Aile = R6
Elev = U7
Pitch = L7
Travel Adjusts are all = 100%
When I measure corner to corner (opposite balls) I get equal numbers and my linkages are equal lengths.
Let me know what you guys think please.

[YBNORMAL]

Your original problem was that you would set a level swash at low stick and then go to high stick then back to low and it wasn't level anymore. Is that problem gone?

If your Tx is at half stick then your subtrims might need a little tweaking since the bellcranks don't appear to be dead on level. Take a look at the pictures that Bob put up that show the alignment of the pitch/aileron and elevator bellcranks.

The elevator bellcrank should be centered in the hole in the frame at half stick. The Ail and Pit bellcranks should show a straight line from the pivot of the bellcrank through the ball mount to the swash and onto the pivot for the elevator bellcrank.

YB

[DaweMD]

This is done at half stick. If you look at the one pic showing the muffler side you can see that the elevator is half way in the hole like bob showed. If I move the pitch and aileron bell crank up than it throws the swash off level.

[DaweMD]

[QUOTE=YBNORMAL;4020976]Your original problem was that you would set a level swash at low stick and then go to high stick then back to low and it wasn't level anymore. Is that problem gone?

If your Tx is at half stick then your subtrims might need a little tweaking since the bellcranks don't appear to be dead on level. Take a look at the pictures that Bob put up that show the alignment of the pitch/aileron and elevator bellcranks.

The elevator bellcrank should be centered in the hole in the frame at half stick. The Ail and Pit bellcranks should show a straight line from the pivot of the bellcrank through the ball mount to the swash and onto the pivot for the elevator bellcrank.

The problem with the swash at different stick positions with the leveler on did not seem to go away, so I put the head on and leveled based on the head geometry.

[DaweMD]

I can move the pitch and aileron bell cranks up but than I would need to adjust the 2 front linkages off of the 55mm original measurement.

[YBNORMAL]

Originally Posted by DaweMD

This is done at half stick. If you look at the one pic showing the muffler side you can see that the elevator is half way in the hole like bob showed. If I move the pitch and aileron bell crank up than it throws the swash off level.

Originally Posted by DaweMD

I can move the pitch and aileron bell cranks up but than I would need to adjust the 2 front linkages off of the 55mm original measurement.

Yup, you would, that is ok. Getting your all of your bellcranks level at 50 in 50 out (mid stick) is more important than staying with the original measurement. You want to get all your servos/bellcranks level (using as little subtrim as possible, even if it means flopping the horns around to get the lowest ST value) Then get the swash level using the pitch and aileron links. The length of the elevator is fixed obviously.

Then go ahead and use the servo travel to level at high and low stick. Remember that depending on your Tx you may have to nudge the cyclic this way or that to get on the right "side" of the travel that you want to adjust.

YB

[Bob O]

+1 to everything YB wrote.

Sent from my phone